The most common side effects when taking quetiapine are: drowsiness, dizziness, dry mouth, mild asthenia, constipation, tachycardia, orthostatic hypotension and dyspepsia.
The use of quetiapine, as well as other antipsychotics, may be accompanied by weight gain, fainting, malignant neuroleptic syndrome, leukopenia, neutropenia, and peripheral edema.
The frequency of adverse reactions is given in the following gradation: very often (≥ 1/10); often (≥ 1/100, <1/10); infrequently (≥ 1/1000, <1/100); rarely (≥ 1/10 000, <1/1000); very rarely (<1/10 000), including cases whose frequency is not known.
From the central nervous system: very often - drowsiness2, dizziness4, headache; often - dysarthria, unusual and nightmarish dreams, fainting4, extrapyramidal symptoms; infrequently - convulsions1, restless legs syndrome; very rarely - tardive dyskinesia6.
From the side of the cardiovascular system: often - orthostatic hypotension, tachycardia4.
From the gastrointestinal tract: very often - dry mouth; often - constipation, indigestion; infrequently - dysphagia; rarely - jaundice6; very rarely - hepatitis6.
From the respiratory system: often - rhinitis.
On the part of the blood system: often - leukopenia1; infrequently - eosinophilia; frequency not known - neutropenia1 .
From the immune system: infrequently - hypersensitivity reaction; very rarely - anaphylactic reactions6.
From the skin: very rarely - angioedema6, Stevens-Johnson syndrome6.
Metabolic disorders: very rarely - diabetes mellitus1,5,6.
Changes in laboratory and instrumental indicators: very often - an increase in the concentration of triglycerides, total cholesterol (mainly low-density lipoprotein cholesterol); often - weight gain, increased activity of hepatic transaminases (aspartate aminotransferase (ACT) and alanine aminotransferase (ALT))3, decrease in the number of neutrophils, hyperglycemia7; infrequently - increased activity of creatine phosphokinase, not associated with malignant neuroleptic syndrome, thrombocytopenia.
Other: very often - withdrawal syndrome; often - asthenia, peripheral edema, blurred vision; rarely - priapism, malignant neuroleptic syndrome.
1. See section "Special instructions".
2. Drowsiness usually occurs within the first 2 weeks after initiation of therapy and is usually resolved against the backdrop of continued use of quetiapine.
3. Perhaps an asymptomatic increase in activity ACT, ALT and γ-glutamyltranspeptidase (GGT) in the blood serum, as a rule, reversible against the background of continued use of quetiapine.
4. Like other antipsychotics quetiapine often causes orthostatic hypotension, which is accompanied by dizziness, tachycardia and in some cases - fainting, especially at the beginning of therapy.
5. Very rare cases of decompensation of diabetes mellitus have been noted.
6. The frequency of this side effect was estimated based on the results of post-marketing surveillance.
7. An increase in fasting blood glucose> 126 mg / dl (> 7.0 mmol / L) or post-prandial glucose> 200 mg / dl (> 11,1 mmol / l), at least for a single application.
Interval lengthening QT, ventricular arrhythmia, sudden death, cardiac arrest and bidirectional ventricular tachycardia are considered side effects of neuroleptics.
Quetiapine therapy is associated with a small dose-dependent decrease in the concentration of thyroid hormones, in particular, total thyroxine (T4) and free T4. Maximum reduction in total and free T4 registered at the 2 nd and 4 th week of quetiapine therapy without further decrease in the concentration of hormones during long-term treatment. Thereafter, there were no signs of clinically significant changes in the concentration of thyroid-stimulating hormone.In almost all cases, the concentration of total and free T4 returned to the baseline after quetiapine therapy was discontinued regardless of the duration of treatment. A slight decrease in total triiodothyronine (T3) and the reverse T3 It was noted only when high doses were used. The level of thyroxine-binding globulin (TSH) remained unchanged, and there was no increase in the thyroid-stimulating hormone (TSH) level.